1. Field of the Invention
This invention relates generally to semiconductor products manufacturing, and, more particularly, to a method and apparatus for performing data stacking in an orderly manner for efficient run-to-run control in manufacturing of semiconductor devices.
2. Description of the Related Art
The technology explosion in the manufacturing industry has resulted in many new and innovative manufacturing processes. Today""s manufacturing processes, particularly semiconductor manufacturing processes, call for a large number of important steps. These process steps are usually vital, and therefore, require a number of inputs that are generally fine-tuned to maintain proper manufacturing control.
The manufacture of semiconductor devices requires a number of discrete process steps to create a packaged semiconductor device from raw semiconductor material. The various processes, from the initial growth of the semiconductor material, the slicing of the semiconductor crystal into individual wafers, the fabrication stages (etching, doping, ion implanting, or the like), to the packaging and final testing of the completed device, are so different from one another and specialized that the processes may be performed in different manufacturing locations that contain different control schemes.
Among the important aspects in semiconductor device manufacturing are RTA control, chemical-mechanical (CMT) control, etching, and overlay control. Overlay is one of several important steps in the photolithography area of semiconductor manufacturing. Overlay process involves measuring the misalignment between two successive patterned layers on the surface of a semiconductor device. Generally, minimization of misalignment errors is important to ensure that the multiple layers of the semiconductor devices are connected and functional. Generally, after the photolithography process is performed on a semiconductor device, an etch process is performed on the semiconductor device for forming a plurality of subsections within a semiconductor device, such as a gate. As technology facilitates smaller critical dimensions for semiconductor devices, the need for reduced of errors increases dramatically.
Generally, process engineers currently analyze the process errors a few times a month. The results from the analysis of the process errors are used to make updates to process tool settings manually. Generally, a manufacturing model is employed to control the manufacturing processes. Some of the problems associated with the current methods include the fact that the process tool settings are only updated a few times a month. Furthermore, currently the process tool updates are generally performed manually. Many times, errors in semiconductor manufacturing are not organized and reported to quality control personal. Often, the manufacturing models themselves incur bias errors that could compromise manufacturing quality.
Generally, a set of processing steps is performed on a lot of wafers on a semiconductor manufacturing tool called an exposure tool or a stepper, followed by processing of the semiconductor wafers in etch tools. The manufacturing tool communicates with a manufacturing framework or a network of processing modules. The manufacturing tool is generally connected to an equipment interface. The equipment interface is connected to a machine interface to which the stepper is connected, thereby facilitating communications between the stepper and the manufacturing framework. The machine interface can generally be part of an advanced process control (APC) system. The APC system initiates a control script based upon a manufacturing model, which can be a software program that automatically retrieves the data needed to execute a manufacturing process. Often, semiconductor devices are staged through multiple manufacturing tools for multiple processes, generating data relating to the quality of the processed semiconductor devices. Many times, errors can occur during the processing of semiconductor devices. Furthermore, manufacturing data that is often acquired in different sequences resulting in data sets that are out of order. Manufacturing data sets that are out of order causes additional difficulties in sorting through manufacturing errors and correcting them.
The present invention is directed to overcoming, or at least reducing the effects of, one or more of the problems set forth above.
In one aspect of the present invention, a method is provided for organizing production data. At least one process run of semiconductor devices is performed. At least one manufacturing tag associated with the process run of semiconductor devices is recorded. Metrology upon at least one of the process run of semiconductor device is performed for acquiring metrology data. A metrology data stackification process is performed upon the metrology data using the manufacturing tag for organizing and stacking the metrology data. At least one control parameter is modified based upon the stacked metrology data.
In another aspect of the present invention, an apparatus is provided for organizing production data. The apparatus of the present invention comprises: a processing tool for processing a production run of semiconductor wafers; a metrology tool coupled with the processing tool and being capable of acquiring metrology data relating to the processed semiconductor wafers; a metrology data stacking unit coupled with the metrology tool and being capable of stacking the metrology data; a computer system coupled with the metrology data stacking unit and being capable of controlling directing and storing metrology data bi-directionally to and from the metrology data stacking unit; a control parameter filter unit coupled with the computer system and being capable of filtering data from the metrology data stacking unit; and a manufacturing model coupled with the computer system and the processing tool, the manufacturing model being capable of modifying control parameters in response to the filtering data from the metrology data stacking unit, for controlling the processing tool.